1. Field of the Invention
This invention relates to a surgical cutting instrument and particularly to a cutter having four disposable and replaceable blades arranged for excising square plugs from a recipient area of the scalp preparatory to receiving square donor plugs in hair transplant surgery, each blade having two cutting edges, one edge disposed in guillotine fashion to facilitate the initial downward axial cut, the other edge coactingly providing a sharp point and means for effecting a sideward rotational cut.
2. Description of the Prior Art
The current preferred technique of hair transplant surgery utilizes the removal of a strip graft from the donor area which, when closed, leaves only a linear scar. In the recipient area, strip grafts may be used to establish the hair line while plug grafts, originally cylindrical, that is circular in cross-section, were used behind the hair line. On the recipient site, the plug grafting is performed in several steps utilizing a staggered or spaced pattern and then filling in between previous grafts at a later date. This allows for preservation of the blood circulation and results in denser growth of hair from each of the plug grafts. Formerly, in preparing the recipient sites, cylindrical plugs were removed by a rotating circular cutter which provided cylindrical holes for correspondingly sized donor plugs which may be removed from the donor sites in a similar manner.
It was then suggested that the donor strips be also used as a source of plug grafts by cutting the strips into squares thereby enabling substantially all the hair follicles removed as strips from the donor site to be utilized as square plugs which provide about 25% more hair for the recipient site than circular plugs of equivalent diameter. The preparation of the recipient site to receive the square donor plugs requires the removal of scalp to form square, that is, substantially hexahedral, holes having predetermined dimensions cut to relatively close tolerances. A square shaped cutter of the conventional cookie or die cutter variety, which is inherently difficult to maintain in a sharpened condition, has proved to be totally ineffective and impractical for this purpose, in that an excessive amount of force must be applied to achieve the required depth of cut and, when so accomplished, the cut fails to be sufficiently sharp and clean, which is a desirable factor in promoting healing. There is, therefore, an urgent need for a practical, efficient, easy to use, instrument for cutting these square holes in the recipient area of the scalp which will overcome the above mentioned problems and achieve satisfactory results so that the advantages of the square plug technique may be realized.